as i was coming home tonight dash lights dimmed then failed warning lights all came on then car overheated any ideas? battery is now flat.
If the auxiliary/fan belt snapped, then the first thing you should have noticed is the red charge light coming on, then as you turned off to check, you'd have noticed that you'd lost all assistance of your steering. It would've taken a mile or two on driving for the engine to overheat. As for the battery now being flat,
I've no idea. I agree with Brickhead but was trying to be diplomatic

I can say all this cos all the above happened in that order to me a few weeks ago when my fan belt snapped.

My battery had enough charge to restart my car 3 times as I started it to coast down a long hill on my way home and then start it to drive it up the ramp of the recovery truck.